1. Field of the Invention
The present invention relates to a curtain airbag device for a car, and more particularly, to a curtain airbag device for a car which can advance the point of time at which a cushion is fully deployed by smoothly supplying gas into the cushion from a fill hose.
2. Description of the Conventional Art
Recently, people are getting more and more interested in safety in car accidents as well as functionality and convenience of a car and putting more importance on it. As a result, the current tendency is that various kinds of safety devices are provided at a car.
Generally, an airbag system is a safety device for a passenger, which is for minimizing the risk of the passenger being injured, caused by directly hit with a car structure, by expanding an airbag between the passenger and the car structure at a car crash.
Such an airbag system is installed at each region of a car according to needs, and is classified into a driver seat airbag device mounted within a steering wheel for protecting a passenger sitting on the driver seat in the upper body and head at head-on collision, a front passenger seat airbag device mounted on the upper side of a globe box for protecting a passenger sitting on the front passenger driver seat, and a curtain airbag device installed in the sides of a car for protecting a passenger, being expanded between the passenger and the doors at a side collision.
The curtain airbag is installed along the roof rail of a car, which is for preventing a passenger from falling out of the car by protecting the passenger in the head at a side collision or in a turnover accident after a side collision.
FIG. 1 is a cross sectional view of a curtain airbag according to the conventional art.
The curtain airbag device for a car according to the conventional art includes: a cushion 102 longitudinally installed along a roof rail and being expandable between a passenger and the car door when the internal pressure increases; an inflator 104 connected to the cushion 102 and for supplying compressed gas into the cushion 102 so as to increase the internal pressure of the cushion 102 at a side collision; and a fill hose 106 longitudinally installed within the cushion 102 along the roof rail, connected to the inflator 104 and for guiding the compressed gas generated in the inflator 104 into the cushion 102.
The fill hose 106 is constructed in a manner that one end is connected to the inflator 104 and the other end is blocked, and a plurality of gas discharge openings 120, 122 and 124 is formed at regular intervals in a longitudinal direction of the fill hose 106 so that the compressed gas in the fill hose 106 can be emitted into the cushion 102.
The gas discharge openings 120, 122 and 124 of the fill hose 106 includes a first group gas discharge opening 120 formed nearest to the inflator 104, a second group gas discharge opening 122 placed in the middle of the fill hose 106, and a third group gas discharge opening 124 formed at the tip end portion of the fill hose 106.
Such a fill hose 106 is formed from fabric and rubber. When the compressed gas of the inflator 104 is supplied thereinto, the volume of the fill hose 106 is changed to a round bar type.
The operation of the thus-constructed curtain airbag device for the car according to the conventional art will now be described.
In the event of a side collision of a vehicle, as the inflator 104 bursts according to a signal applied from a collision sensor, the compressed gas stored in the inflator 104 is supplied into the fill hose 106. Then, as the volume of the fill hose 106 is changed to a round bar type, the compressed gas is supplied into the cushion 102 through the plurality of gas discharge openings 120, 122 and 124 formed on the fill hose 106. Thus, the cushion 102 is expanded, thereby protecting a passenger.
However, in the thus-constructed curtain airbag device for the car according to the conventional art, when the compressed gas is supplied to the fill hose 106, the volume of the fill hose 106 is changed to a round bar type, and the gas discharge openings 120, 122 and 124 are formed perpendicular to the direction of gas flow. Therefore, the compressed gas in the fill hose 106 is not smoothly emitted into the cushion 102, and accordingly, the full deployment time of the cushion 102 is delayed, thereby being unable to safely protect the passenger.
Especially, the flow rate of the compressed gas in the fill hose 106 is very high at the inlet region of the fill hose 106 adjacent to the inflator 104. Hence, the compressed gas in the fill hose 106 is not relatively more emitted from the first group gas discharge openings 120 of the fill hose 106. Consequently, the cushion 102 may be eccentrically expanded.